A child resist battery door is an important feature for a hearing aid which is to be used by young children. Also for hearing aid users who are mentally ill or retarded, it can be of importance that the battery door cannot be inadvertently opened. U.S. Pat. No. 5,386,476 disclose a prior art hearing aid with a locking device designed to avoid inadvertent opening of the battery compartment. The locking device comprises a displaceable pin, which can be maneuvered through an opening in the battery chamber by means of a pointed or thin object, e.g. a mandrel-shaped tool or the like. The pin is slidable and in one position it blocks the opening movement of the battery door and in a second position it is in-active and the door can be opened. Another prior art hearing aid with child proofing is described in WO 2004073351 A1. None of the prior art hearing aid constructions allow a simple and efficient construction with a safe prevention of inadvertent opening of the battery drawer.